Research by the food charity Sustain has revealed that some of the UK’s largest contract caterers are serving fish deemed by the Marine Conservation Society (MCS) to be “at risk” because of overfishing, those produced unsustainably or those produced with slavery in the supply chain.

The caterers, some of which will be contracted at venues used by charities, include Sodexo, Compass Group UK and Ireland and ISS.

MCS identify 63 species and types for their “red” list of ones to avoid eating. These include fish where the sustainability is improved by selection of method of catching, area caught in or farmed possibilities and included on the list are cod, haddock, herring, seabass, bream, eel, grouper, halibut, lobster, marlin, grey mullet, plaice, pollock, whitebait, rays, Atlantic salmon, scallops, shark, skate, sole, squid, swordfish and tuna.

Check the MCS website before eating, if you don’t want to be part of the problem.